The present invention relates to improvements in methods of and in apparatus for splicing together running webs of paper or the like, e.g., webs of paper or other wrapping material for use in the making of plain or filter cigarettes, cigars, cigarillos and/or other rod-shaped smokers' products. More particularly, the invention relates to improvements in methods of and in apparatus for splicing trailing ends of expiring webs or strips of paper or the like to leading ends of fresh webs in such a way that the leading and trailing ends need not be adhesively and/or thermally secured to each other. Still more particularly, the invention relates to improvements in methods of and in apparatus for securing the leading and trailing ends of pairs of running webs or strips of deformable material to each other while the two ends advance lengthwise, in the same direction, adjacent one another, at or close to identical speeds and are pressed against each other. Splicing undertakings of such character include folding and knurling.
Methods and apparatus for splicing the leading ends of fresh running webs to the trailing ends of expiring running webs are resorted to, among others, in the tobacco processing industry, e.g., to connect the leader of a rotating fresh bobbin or reel of convoluted cigarette paper to the trailing end of a rotating nearly expired bobbin or reel of cigarette paper in such a way that the delivery of cigarette paper to the wrapping station of a cigarette maker need not be interrupted or decelerated. This greatly reduces the number of rejects and enhances the output, especially in modern high-speed machines which are designed to turn out well in excess of 10,000 rod-shaped smokers' products per minute.
Presently known methods and apparatus of the above outlined character are disclosed, for example, in the assignee's German patent No. 693 00 282, Utility Model No. 1 995 937 and published German patent applications Nos. 1 532 203 and 1 532 204. U.S. Pat. No. 3,089,661 granted May 14, 1963 to Malcolm E. Phillips, Jr. et al. discloses an automatic cigarette paper splicer wherein a fresh convoluted cigarette paper web is accelerated to the speed of a running (expiring) cigarette paper web by taking into consideration the mass of the supply (such as a bobbin) of fresh convoluted web, the speed of the expiring bobbin of convoluted web and the tensional strength of the webs. Two rotary splicing sectors are provided to connect the leading end to the trailing end when the speed of the leading end matches that of the trailing end as well as the peripheral speeds of the sectors. The splicing involves or can involve one revolution of each sector about its respective axis. The final steps of the patented splicing operation include the severing of those (foremost and rearmost) ends of the spliced-together webs which respectively extend forwardly and rearwardly of the finished splice. Such final steps are carried out by knives which are actuated in dependency upon the positions of the splicing sectors.
An advantage of the automatic splicer which is disclosed in the U.S. Pat. No. 3,089,661 to Phillips et al. is that the operation of the web processing machine (e.g., a machine which confines a continuous rod-like filler of natural, substitute or reconstituted tobacco in a continuous web of cigarette paper or the like) need not be interrupted when the supply of a reel of convoluted web-like wrapping material is exhausted, i.e., that the splicing operation can be carried out while the expiring web and the fresh web are being moved at the prescribed speed of the wrapping material entering the processing machine.
Another known mode of splicing the leader of a fresh web to the trailing end of a moving expiring web in a cigarette maker is to resort to a magazine which is designed to temporarily store a length of the expiring web. Such proposals are not entirely satisfactory because the magazine takes up a substantial amount of space in a cigarette making or like plant wherein hundreds of wrapping machines are confined in a common hall.